Organic phosphates as wear inhibitors for iron carbonyl



Patented Mar. 27, 1951 ORGANIC PHOSPHATES AS WEAR INHIBI- TORS FOR IRONCARBONYL Howard Clinton Cross, Columbus, Ohio, assignor, by mesneassignments, to Ethyl Corporation, New York, N. Y., a corporation ofDelaware No Drawing.

Application August 5, 1949,

Serial No. 108,854

2 Claims.

This invention relates to antiknock mixtures and particularly to amixture of iron carbonyl and an inhibitor which reduces the engine wearcaused by the use of the iron carbonyl.

Ironpentacarbonyl is a good antiknock agent and as such comparesfavorably with tetraethyllead. It has the economic advantage of beingcheap. However, when a fuel containing it is burned in internalcombustion engines, it has the disadvantage of causing wear in anengine, particularly wear of the piston rings. The abrasive propertiesof iron carbonyl decomposition products have effectively prevented itsuse commercially.

It is therefore an object of this invention to provide a wear inhibitorwhich substantially reduces such engine wear. I have found that gasolinesoluble organic phosphates substantially reduce the engine wear causedby the use of iron carbonyl. It is believed that it is the phosphorus inthe phosphate radical which reduces the wear and that the organicradical has little if any effect on the engine wear and serves primarilyas a means of getting the phosphate radical into solution in thegasoline, and transplanting it into the combustion chamber of theengine. Therefore, my invention is not limited to the specific organicradicals given herein.

The organic phosphates of my invention correspond to the general formulaRsPO-z in which R is an organic radical such as an aryl, alkyl, or analkenyl. Examples of such organic phosphates are as follows: tricresylphosphate, triphenol phosphate, trivinyl phosphate, tripropenylphosphate, triethyl phosphate, tripropyl phosphate, and tributylphosphate.

My invention can be further understood by referring to the followingworking examples. A quantity of fuel was prepared by blending in acommercial motor gasoline a mixture of 0.312' gram of phosphorus in theform of triethyl phosphate, 3 cubic centimeters of ironpentacarbonyl,all quantities of added materials based on one gallon of fuel. This fuelmixture was burned in a four cycle single cylinder internal combustionengine for 150 hours. the cylinder and the loss of weight of the pistonrings were measured to indicate the resulting wear. In a similaroperation keeping all quantities of materials used and engine conditionsthe same except that no wear inhibitor was used, the same measurementsfor indicating wear were made. Comparing these two operations as toamount of wear obtained with and without an inhibitor and taking thewear resulting from the use of iron carbonyl alone as 100% the operationusing the triethyl phosphate inhibitor resulted in only 32% of the wearobtained for iron carbonyl alone. Thus the addition of a small quantityof the inhibitor of the triethyl phosphate to a fuel The internaldiameter of containing iron carbonyl reduces the wear by 68 compared ofthat obtained with the same fuel without the inhibitor. In anotheroperation in place of triethylphosphate, tricresyl phosphate was used,the quantities of all materials being the same as in the above example.Comparing the wear obtained on the test operating on the fuel containinga mixture of tricresyl phosphate and ironpentacarbonyl with the fuelcontaining ironpentacarbonyl alone, the tricresyl phosphate inhibitorresulted in only 51% of the wear obtained with the iron carbonyl alone.In a similar test substituting trimethyl phosphate for triethylphosphate substantially the same reduction in wear using the trimethylphosphate was obtained.

Generally, the amount of iron carbonyl to be used as an antiknock infuels for engines is between about 1 and 3 cubic centimeters per gallonof fuel. The amount of wear inhibitor used depends on the amount of ironcarbonyl used and the inhibitor employed. In all cases the amount ofinhibitor used is small and varies between approximately 0.05 to 0.25gram of phosphorus in the form of the organic phosphate to one cubiccentimeter of iron carbonyl.

My wear inhibitors can be used in mixtures containing iron carbonyl andother antiknock materials such as lead antiknock compounds. Also amixture of iron carbonyl and one of my wear inhibitors can be used as anauxilary antiknock fluid in an engine operating on a leaded gasoline.

I claim:

1. An antiknock mixture consisting essentially of iron carbonyl and awear inhibitor in an amount suiiicient to reduce Wear and deposits onengine parts caused by iron pentacarbonyl, said wear inhibitorconsisting essentially of from 0.05 to 0.25 gram of phosphorus in theform of an organic phosphate to 1 cubic centimeter of ironpentacarbonyl, said organic phosphate being soluble in gasoline andhaving the general formula R3PO4 in which R is selected from the classconsisting of alkyl, aryl, and alkenyl.

2. The product of claim 1 in which the wear inhibitor is triethylphosphate.

HOWARD CLINTON CROSS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,940,096 Mueller-Cunradi et a1.Dec. 19, 1933 2,140,627 Hocking Dec. 20, 1938 2,149,221 Lamping Feb. 28,1938 2,291,442 Bass et a1 July 28, 1942

1. AN ANTIKNOCK MIXTURE CONSISTING ESSENTIALLY OF IRON CARBONYL AND AWEAR INHIBITOR IN AN AMOUNT SUFFICIENT TO REDUCE WEAR AND DEPOSITSENGINE PARTS CAUSED BY IRON PENTACARBONYL, SAID WEAR INHIBITOR CONISTINGESSENTIALLY OF FROM 0.05 TO 0.25 GRAM OF PHOSPHORUS IN THE FORM OF ANORGANIC PHOSPHATE TO 1 CUBIC CENTIMETER OF IRON PENTACARBONYL, SAIDORGANIC PHOSPHATE BEING SOLUBLE IN GASOLINE AND HAVING THE GENERALFORMULA R3PO4 IN WHICH R IS SELECTED FROM THE CLASS CONSISTING OF ALKYL,ARYL, AND ALKENYL.